U.S. Pat. No. 2,714,456, referred to above, describes a mechanical parking system in which cars are loaded in stalls, or bins, on the various stories of a multi-tier parking unit, by a suitable crane mechanism. As pointed out in the patent, such systems are in general well known to the art, and usually utilize a crane-way running between two multi-story parking structures having a row of stalls on each floor to receive cars from elevator mechanisms which move vertically and horizontally in the crane-ways. In the structure described in the patent, elevator mechanisms are provided in the crane-ways which, are adapted to move both vertically and horizontally to service the various stalls on the different floors of the adjacent parking structures.
An entrance conveyor is provided in one of the crane-ways of the parking system described in the patent which is adapted to move cars from certain stalls of the ground floor of one parking unit, across the crane-way to the ground floor of a second parking unit. Similarly, exit conveyor means are provided in the system described in the patent in a second crane-way to move cars from certain stalls of the ground floor of the second parking unit across the second crane-way to the ground floor of a third parking unit. In order to accommodate the conveyor means in the system described in the patent, the elevator mechanisms are supported from one or more of the upper stories of the various parking units, so that the elevator mechanisms may move horizontally back and forth along the crane-ways and pass over the various conveyor means without interfering in any way with the conveyor means, or with cars transported thereby. The elevator mechanism of the present invention is similarly suspended above the ground floor of the parking unit, for the same reasons.
As mentioned above, the particular elevator mechanism of the present invention is mounted on chain-type bearings, as will be described, to facilitate horizontal movement of the elevator mechanism back and forth in the individual crane-ways without any tendency for it to bind or lock with the rails. Also, one or more vertical lead screws are provided in the elevator mechanism of the invention, in conjunction with the usual winch and counterweight components, to provide an auxiliary hoisting and redundancy safety means for the elevator, and for other reasons to be described.